The invention relates to a junction field effect transistor (JFET) affording high blocking voltage capability, including AC application.
A power JFET is provided having a common drift region between a pair of spaced first and second stacks of alternating conductivity type layers forming a plurality of channels. Bidirectional current is conducted through the channels and common drift region in an ON state. In the OFF state, current flow is blocked by depletion region pinch-off in the channels.
Linear geometry enables desirable control of breakdown voltage, and in turn a higher blocking voltage capability. ON state conduction current flows longitudinally horizontally through the common drift region, with consequent desirable bulk effect characteristics.
The channels are stacked vertically at opposite ends of the drift region, with current flowing horizontally through the channels in the ON state, and being pinched-off in the OFF state by vertical depletion region spreading. Multiple channels reduce the channel component of the ON state resistance.
Field shaping regions are provided in the common drift region for straightening field lines therein and reducing gradient curvature crowding of the field lines, e.g. radius or corner curvature. The field shaping regions are in the bulk drift region, removed from the active area of the channel junctions between the alternate conductivity layers in the stacks.